Radio-frequency module and communication device

ABSTRACT

A radio-frequency module includes an integrated circuit (IC) device and an external inductor provided outside the IC device. The IC device includes a plurality of low-noise amplifiers, one or more inductors, and a switching circuit. The plurality of low-noise amplifiers includes a plurality of transistors in one to one correspondence. The one or more inductors are coupled to one or more of the plurality of transistors. Each inductor is coupled to the emitter or source of a corresponding one of the plurality of transistors. The switching circuit is coupled between the emitter or source of each of the plurality of transistors and the external inductor. The external inductor is coupled between the switching circuit and ground in series with each of the one or more inductors via the switching circuit.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Japanese patent applicationJP2020-113420, filed Jun. 30, 2020, the entire contents of which beingincorporated herein by reference.

BACKGROUND 1. Field

The present disclosure relates to a radio-frequency module and acommunication device.

2. Description of the Related Art

Japanese Unexamined Patent Application Publication No. 10-126174 (PatentDocument 1) discloses an integrated circuit operable as a low-noiseamplifier that is formed by integrating an amplifier transistor and aninductor coupled to the source or emitter of the amplifier transistor.The inductor in the integrated circuit disclosed in Patent Document 1 isformed by using a metal wire.

SUMMARY

When an inductor is formed by using a metal wire in an integratedcircuit as the known technology described above, the size of theintegrated circuit increases because a space larger than a given size isneeded. When multiple low-noise amplifiers are integrated together, inaddition to spaces for amplifier transistors, spaces for inductors arealso needed, and as a result, the size of the integrated circuit furtherincreases. Moreover, since the inductor coupled to the source or emitterof the amplifier transistor largely affects characteristics of thelow-noise amplifier, there is a need for a low-loss inductor.

Accordingly, the present disclosure provides a small radio-frequencymodule and a small communication device that include a plurality oflow-noise amplifiers with improved characteristics.

A radio-frequency module according to an aspect of the presentdisclosure includes an integrated circuit (IC) device and an externalinductor provided outside the IC device. The IC device includes aplurality of low-noise amplifiers including a plurality of amplifiertransistors in one to one correspondence, one or more inductors coupledto one or more of the plurality of amplifier transistors, each inductorbeing coupled to the emitter or source of a corresponding one of theplurality of amplifier transistors, and a switching circuit coupledbetween the emitter or source of each of the plurality of amplifiertransistors and the external inductor, and the external inductor iscoupled between the switching circuit and ground in series with each ofthe one or more inductors via the switching circuit.

A communication device according to an aspect of the present disclosureincludes a signal processing circuit configured to process aradio-frequency signal and the radio-frequency module described abovethat is configured to communicate the radio-frequency signal between thesignal processing circuit and an antenna.

The present disclosure can provide a small radio-frequency module and asmall communication device that include a plurality of low-noiseamplifiers with improved characteristics.

Other features, elements, characteristics, and advantages of the presentdisclosure will become more apparent from the following detaileddescription of preferred embodiments of the present disclosure withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit configuration diagram of a radio-frequency moduleand a communication device according to an embodiment;

FIG. 2 is a circuit configuration diagram of an integrated circuit (IC)device of the radio-frequency module according to the embodiment;

FIG. 3 is a sectional view of the radio-frequency module according tothe embodiment;

FIG. 4 is a sectional view of a radio-frequency module according to afirst modification of the embodiment;

FIG. 5 is a sectional view of a radio-frequency module according to asecond modification of the embodiment; and

FIG. 6 is a sectional view of a radio-frequency module according to athird modification of the embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a radio-frequency module and a communication deviceaccording to a preferred embodiment of the present disclosure will bedescribed in detail with reference to the drawings. It should be notedthat the embodiment described below is one specific example of thepresent disclosure. Consequently, for example, numerical values, shapes,materials, constituent elements, arrangements of the constituentelements, connection modes of the constituent elements, steps, and theorder of the steps given in the following embodiment are mere examplesand are not intended to limit the present disclosure. Among theconstituent elements in the following embodiment, constituent elementsnot recited in any of the independent claims are described as arbitraryconstituent elements.

The drawings are schematic drawings and are not always depicted in anexact manner. Thus, for example, the drawings are not consistent interms of scale. Like reference symbols are used to denote substantiallylike configurations in the drawings, and redundant descriptions thereofare omitted or simplified.

In the circuit configuration of the present disclosure, the expression“directly coupled” denotes that a circuit element is directly coupled toanother circuit element by using a connection terminal and/or a wiringconductor without intermediate connection with still another circuitelement. By contrast, the expression “coupled” includes not only thecase in which a circuit element is directly coupled to another circuitelement by using a connection terminal and/or a wiring conductor butalso the case in which a circuit element is electrically coupled toanother circuit element via still another circuit element. Theexpression “coupled between A and B” denotes that a circuit element iscoupling to both A and B while the circuit element is positioned betweenA and B.

With regard to the component arrangement of the present disclosure, theexpression “when a substrate is viewed in plan view” denotes thatobjects orthogonally projected on a major surface of the substrate areviewed in a direction perpendicular to the major surface of thesubstrate. Additionally, the expression “A coincides with B when asubstrate is viewed in plan view” denotes that at least a part of theregion of A orthogonally projected on a major surface coincides with atleast a part of the region of B orthogonally projected on the majorsurface.

Furthermore, the expression “a component is disposed at a substrate”includes the case in which the component is positioned in contact withthe substrate, the case in which the component is positioned over thesubstrate without contact with the substrate (for example, the componentis stacked on a component disposed on the substrate), and the case inwhich the component is partially or entirely embedded in the substrate.The expression “a component is disposed at a major surface of asubstrate” includes the case in which the component is positioned incontact with the major surface of the substrate, the case in which thecomponent is positioned over the major surface without contact with themajor surface, and the case in which the component is partially embeddedin the substrate at the major surface.

In this specification, words used to express relationships betweenelements, such as parallel and vertical, and numerical ranges do notnecessarily denote the exact meanings but denote substantially the samemeanings involving, for example, several percent differences.

Embodiment 1. Circuit Configuration of Radio-Frequency Module andCommunication Device

Hereinafter, a circuit configuration of a radio-frequency module 1 and acommunication device 5 according to the present embodiment will bedescribed with reference to FIG. 1. FIG. 1 is a circuit configurationdiagram of the radio-frequency module 1 and the communication device 5according to the present embodiment.

1-1. Circuit Configuration of Communication Device

Firstly, a circuit configuration of the communication device 5 will bedescribed. As illustrated in FIG. 1, the communication device 5according to the present embodiment includes the radio-frequency module1, an antenna 2, a radio-frequency integrated circuit (RFIC) 3, and abase-band integrated circuit (BBIC) 4. Hereinafter, the constituentelements of the communication device 5 will be described in order.

The radio-frequency module 1 communicates a radio-frequency signalbetween the antenna 2 and the RFIC 3. The circuit configuration of theradio-frequency module 1 will be described later. The term “circuit”, isused herein to be synonymous with “circuitry” (i.e., one or morecircuits). Thus, when referencing RFIC 3, is should be understood thatRFIC 3 is circuitry that may include one or more separate circuits.

The antenna 2 is coupled to the antenna connection terminal 90 of theradio-frequency module 1. The antenna 2 receives a radio-frequencysignal from outside and outputs the radio-frequency signal to theradio-frequency module 1.

The RFIC 3 is an example of a signal processing circuit for processing aradio-frequency signal. Specifically, the RFIC 3 processes ahigh-frequency receive signal inputted through a receive path of theradio-frequency module 1 by performing, for example, downconversion andoutputs the processed receive signal generated by the signal processingto the BBIC 4. In this context the term “high-frequency” is meant torefer to a signal between baseband and the RF channel frequency, and notnecessarily the 3 MHz to 30 MHz “HF band”. The RFIC 3 includes acontroller for controlling, for example, a switch and a low-noiseamplifier of the radio-frequency module 1. The function of thecontroller of the RFIC 3 may be partially or entirely implementedoutside the RFIC 3; for example, the function of the controller may bepartially or entirely implemented in the BBIC 4 or the radio-frequencymodule 1.

The BBIC 4 is a baseband signal processing circuit configured to performsignal processing by using an intermediate frequency band lower thanradio-frequency signals communicated by the radio-frequency module 1.The BBIC 4 processes, for example, image signals used to display imagesand/or sound signals used for calls via a speaker.

In the communication device 5 according to the present embodiment, theantenna 2 and the BBIC 4 are non-essential constituent elements.

1-2. Circuit Configuration of Radio-Frequency Module

Next, a circuit configuration of the radio-frequency module 1 will bedescribed. As illustrated in FIG. 1, the radio-frequency module 1includes low-noise amplifiers 21, 22, and 23, switching circuits 51 and52, filters 61, 62, and 63, matching networks (MNs) 71, 72, and 73, theantenna connection terminal 90, and a radio-frequency output terminal91. The radio-frequency module 1 includes an integrated circuit (IC)device 100. The IC device 100 includes the plurality of low-noiseamplifiers 21, 22, and 23. Additionally, the radio-frequency module 1includes an inductor L (refer to FIG. 2) electrically coupled to the ICdevice 100. The inductor L is not illustrated in FIG. 1.

The antenna connection terminal 90 is an example of an externalconnection terminal. The antenna connection terminal 90 is coupled tothe antenna 2.

The radio-frequency output terminal 91 is an example of an externalconnection terminal. The radio-frequency output terminal 91 isconfigured to provide a radio-frequency signal outside theradio-frequency module 1. The radio-frequency output terminal 91 iscoupled to the RFIC 3.

Each of the low-noise amplifiers 21, 22, and 23 is one of a plurality oflow-noise amplifiers included in the IC device 100. The low-noiseamplifiers 21, 22, and 23 respectively amplify radio-frequency signalsin communication bands A, B, and C. Radio-frequency signals in thecommunication bands are amplified by the corresponding low-noiseamplifiers 21, 22, and 23 and outputted from the radio-frequency outputterminal 91 via the switching circuit 52.

The communication bands A, B, and C are frequency bands determined bystandards organizations for communication systems developed by employingradio access technologies (RATs). The standards organizations include,for example, the 3rd Generation Partnership Project (3GPP) and theInstitute of Electrical and Electronics Engineers (IEEE).

The communication bands A, B, and C are different from each other andused for an identical communication system or communication systemsdifferent from each other. For example, the communication bands A, B,and C are, but not limited to, a 5th Generation New Radio (5GNR) band, aLong Term Evolution (LTE) band, and a Wireless Local Area Network (WLAN)band.

A specific configuration of the low-noise amplifiers 21, 22, and 23 willbe described later with reference to FIG. 2.

Returning to FIG. 1, the filter 61 is coupled between the antennaconnection terminal 90 and the low-noise amplifier 21. The filter 61passes signals in the receive frequency range of a communication band Aout of radio-frequency receive signals inputted from the antennaconnection terminal 90.

The filter 62 is coupled between the antenna connection terminal 90 andthe low-noise amplifier 22. The filter 62 passes signals in the receivefrequency range of the communication band B out of radio-frequencyreceive signals inputted from the antenna connection terminal 90.

The filter 63 is coupled between the antenna connection terminal 90 andthe low-noise amplifier 23. The filter 63 passes signals in the receivefrequency range of the communication band C out of radio-frequencyreceive signals inputted from the antenna connection terminal 90.

The matching network 71 is an input matching network for the low-noiseamplifier 21. The matching network 71 is coupled to an input terminal ofthe low-noise amplifier 21. The matching network 71 is positionedbetween the filter 61 and the low-noise amplifier 21 and directlycoupled to the filter 61 and the low-noise amplifier 21. The matchingnetwork 71 performs impedance matching between the filter 61 and thelow-noise amplifier 21.

The matching network 72 is an input matching network for the low-noiseamplifier 22. The matching network 72 is coupled to an input terminal ofthe low-noise amplifier 22. The matching network 72 is positionedbetween the filter 62 and the low-noise amplifier 22 and directlycoupled to the filter 62 and the low-noise amplifier 22. The matchingnetwork 72 performs impedance matching between the filter 62 and thelow-noise amplifier 22.

The matching network 73 is an input matching network for the low-noiseamplifier 23. The matching network 73 is coupled to an input terminal ofthe low-noise amplifier 23. The matching network 73 is positionedbetween the filter 63 and the low-noise amplifier 23 and directlycoupled to the filter 63 and the low-noise amplifier 23. The matchingnetwork 73 performs impedance matching between the filter 63 and thelow-noise amplifier 23.

The switching circuit 51 is coupled between the antenna connectionterminal 90 and the filters 61, 62, and 63. Specifically, the switchingcircuit 51 includes terminals 511, 512, 513, and 514. The terminal 511is a common terminal. The terminal 511 is coupled to the antennaconnection terminal 90. The terminals 512, 513, and 514 are selectionterminals. The terminals 512, 513, and 514 are respectively coupled tothe filters 61, 62, and 63. In accordance with, for example, a controlsignal from the RFIC 3, the switching circuit 51 can connect acorresponding one of the terminals 512, 513, and 514 to the terminal511. This means that the switching circuit 51 can control connectionbetween the antenna 2 and the filter 61, connection between the antenna2 and the filter 62, and connection between the antenna 2 and the filter63. The switching circuit 51 is implemented as, for example, asingle-pole triple-throw (SP3T) switching circuit. The switching circuit51 is referred to as an antenna switch.

The switching circuit 52 is coupled between the radio-frequency outputterminal 91 and the low-noise amplifiers 21, 22, and 23. Specifically,the switching circuit 52 includes terminals 521, 522, 523, and 524. Theterminal 521 is a common terminal. The terminal 521 is coupled to theradio-frequency output terminal 91. The terminals 522, 523, and 524 areselection terminals. The terminals 522, 523, and 524 are respectivelycoupled to an output terminal of the low-noise amplifier 21, an outputterminal of the low-noise amplifier 22, and an output terminal of thelow-noise amplifiers 23. In accordance with, for example, a controlsignal from the RFIC 3, the switching circuit 52 can connect acorresponding one of the terminals 522, 523, and 524 to the terminal521. This means that the switching circuit 52 can control connectionbetween the RFIC 3 and the low-noise amplifier 21, connection betweenthe RFIC 3 and the low-noise amplifier 22, and connection between theRFIC 3 and the low-noise amplifier 23. The switching circuit 52 isimplemented as, for example, an SP3T switching circuit. The switchingcircuit 52 is referred to as a band selection switch.

One or some of the circuit elements illustrated in FIG. 1 may beexcluded from the radio-frequency module 1. For example, theradio-frequency module 1 only needs to include at least the IC device100 without the other circuit elements.

1-3. Circuit Configuration of IC Device

Next, a circuit configuration of the IC device 100 will be describedwith reference to FIG. 2. FIG. 2 is a circuit configuration diagram ofthe IC device 100 according to the present embodiment.

As illustrated in FIG. 2, the IC device 100 includes the low-noiseamplifiers 21, 22, and 23, inductors L1 and L2, and a switching circuit110. The IC device 100 also includes a connection terminal 101. Theconnection terminal 101 is an external connection terminal of the ICdevice 100. The connection terminal 101 is grounded via the inductor L.

The low-noise amplifier 21 includes a transistor TR1. The transistor TR1is an amplifier transistor configured to amplify a radio-frequencysignal (specifically, a radio-frequency signal in the communication bandA) inputted to an input terminal In1 and output the signal from anoutput terminal Out1.

The transistor TR1 is, for example, a field effect transistor (FET). Thegate of the transistor TR1 is coupled to the input terminal In1 of thelow-noise amplifier 21. The drain of the transistor TR1 is coupled tothe output terminal Out1 of the low-noise amplifier 21. The source ofthe transistor TR1 is coupled to the inductor L1.

The low-noise amplifier 22 includes a transistor TR2. The transistor TR2is an amplifier transistor configured to amplify a radio-frequencysignal (specifically, a radio-frequency signal in the communication bandB) inputted to an input terminal In2 and output the signal from anoutput terminal Out2.

The transistor TR2 is, for example, a FET. The gate of the transistorTR2 is coupled to the input terminal In2 of the low-noise amplifier 22.The drain of the transistor TR2 is coupled to the output terminal Out2of the low-noise amplifier 22. The source of the transistor TR2 iscoupled to the inductor L2.

The low-noise amplifier 23 includes a transistor TR3. The transistor TR3is an amplifier transistor configured to amplify a radio-frequencysignal (specifically, a radio-frequency signal in the communication bandC) inputted to an input terminal In3 and output the signal from anoutput terminal Out3.

The transistor TR3 is, for example, a FET. The gate of the transistorTR3 is coupled to the input terminal In3 of the low-noise amplifier 23.The drain of the transistor TR3 is coupled to the output terminal Out3of the low-noise amplifier 23. The source of the transistor TR3 iscoupled to the switching circuit 110.

The switching circuit 110 is coupled between the source of thetransistor TR1, the source of the transistor TR2, and the source of thetransistor TR3, and the connection terminal 101. The switching circuit110 includes terminals 111, 112, 113, and 114. The terminal 111 is acommon terminal. The terminal 111 is coupled to the connection terminal101. The terminals 112, 113, and 114 are selection terminals. Theterminals 112, 113, and 114 are respectively coupled to the source ofthe transistor TR1, the source of the transistor TR2, and the source ofthe transistor TR3. Specifically, the terminal 112 is coupled to thesource of the transistor TR1 via the inductor L1. The terminal 113 iscoupled to the source of the transistor TR2 via the inductor L2. Theterminal 114 is directly coupled to the source of the transistor TR3.

The switching circuit 110 controls connection between the source of thetransistor TR1 and the inductor L, connection between the source of thetransistor TR2 and the inductor L, and connection between the source ofthe transistor TR3 and the inductor L. Specifically, in accordance with,for example, a control signal from the RFIC 3, the switching circuit 110can connect a corresponding one of the terminals 112, 113, and 114 tothe terminal 111. This means that the switching circuit 110 can controlconnection between the source of the transistor TR1 and the inductor L,connection between the source of the transistor TR2 and the inductor L,and connection between the source of the transistor TR3 and the inductorL. The switching circuit 110 is implemented as, for example, an SP3Tswitching circuit.

The switching circuit 110 is controlled in conjunction with theswitching circuits 51 and 52. For example, when the antenna 2 receives aradio-frequency signal in the communication band A, the terminal 511 iscoupled to the terminal 512 in the switching circuit 51; the terminal521 is coupled to the terminal 522 in the switching circuit 52; and theterminal 111 is coupled to the terminal 112 in the switching circuit110. In this manner, the radio-frequency signal in the communicationband A can be amplified by the low-noise amplifier 21.

In the present embodiment, the source of the transistor TR1, the sourceof the transistor TR2, and the source of the transistor TR3 are allconfigured to be grounded via the switching circuit 110. For example,the terminal 111 is coupled to the terminal 112 in the switching circuit110, and as a result, the source of the transistor TR1 is grounded viathe inductors L1 and L. The terminal 111 is coupled to the terminal 113in the switching circuit 110, and as a result, the source of thetransistor TR2 is grounded via the inductors L2 and L. The terminal 111is coupled to the terminal 114 in the switching circuit 110, and as aresult, the source of the transistor TR3 is grounded via the inductor L.

The inductors L, L1, and L2 each function as a part or all of the sourceinductor of a corresponding one of the transistors TR1, TR2 and TR3included in the IC device 100. The inductors L1 and L2 are provided inthe IC device 100. The inductor L is an example of an external inductorprovided outside the IC device 100. The inductor L is coupled betweenthe connection terminal 101 and the ground. The inductor L is coupled inseries with each of the inductors L1 and L2 via the switching circuit110.

The source inductor is coupled between the source of an amplifiertransistor grounded via the source and the ground. The source inductorcontrols the impedance between the source of an amplifier transistor andthe ground. The impedance is controlled to be an appropriate value, andthus, the amplifier transistor can appropriately amplify an inputradio-frequency signal.

The inductance of the source inductor can be determined in accordancewith the frequency of the radio-frequency signal inputted to theamplifier transistor. Specifically, when the frequency of theradio-frequency signal inputted to the amplifier transistor isrelatively low, the inductance of the source inductor is increased.

In the present embodiment, the transistors TR1, TR2 and TR3 differ fromeach other in terms of the frequency of the radio-frequency signalinputted to each transistor. Thus, the transistors TR1, TR2 and TR3 alsodiffer from each other with respect to the inductance of the sourceinductor. For example, it is assumed that the frequency of aradio-frequency signal in the communication band A inputted to thetransistor TR1 is the lowest and the frequency of a radio-frequencysignal in the communication band C inputted to the transistor TR1 is thehighest. In this case, the inductance of the source inductor of thetransistor TR1 is the largest, and the inductance of the source inductorof the transistor TR3 is the smallest.

In the present embodiment, the source inductor of the transistor TR1 isconstituted by the inductor L1 in the IC device 100 and the inductor Loutside the IC device 100 coupled in series with each other. The sourceinductor of the transistor TR2 is constituted by the inductor L2 in theIC device 100 and the inductor L outside the IC device 100 coupled inseries with each other. The source inductor of the transistor TR3 isconstituted by only the inductor L outside the IC device 100.

As described above, the external inductor L is shared by the transistorsTR1, TR2, and TR3. The inductance of the inductor L is determined to bea value suitable for the source inductor of the transistor TR3. Toprovide compensation for insufficient inductance of the transistors TR1and TR2, the inductors L1 and L2 are individually provided in the ICdevice 100.

The Q factor of the inductor L outside the IC device 100 is usuallyhigher than the Q factor of the inductor L1 and the Q factor of theinductor L2 provided inside the IC device 100. Using the inductor L withhigh Q factor and low loss enhances electrical characteristics of thelow-noise amplifiers 21, 22, and 23.

For example, the inductance of the inductor L is larger than both theinductance of the inductor L1 and the inductance of the inductor L2.Since the inductance of the inductor L with high Q factor and low lossoccupies as much inductance required for the source inductor aspossible, electrical characteristics can be enhanced.

It should be noted that another inductor may also be coupled between thetransistor TR3 and the terminal 114.

2. Component Arrangement of Radio-Frequency Module

Next, a component arrangement of the radio-frequency module 1 configuredas described above will be described with reference to FIG. 3.

FIG. 3 is a sectional view of the radio-frequency module 1 according tothe present embodiment. As illustrated in FIG. 3, the radio-frequencymodule 1 includes, in addition to the circuit components including thecircuit elements illustrated in FIG. 1, a chip inductor 120, a modulesubstrate 130, resin members 140 and 141, a plurality of post electrodes150, and a shield electrode layer 160.

The module substrate 130 includes major surfaces 131 and 132. The modulesubstrate 130 may be, for example, a low temperature co-fired ceramics(LTCC) substrate having a layered structure composed of a plurality ofdielectric layers, a high temperature co-fired ceramics (HTCC)substrate, a component-embedded substrate, a substrate including aredistribution layer (RDL), or a printed board, but the module substrate130 is not limited to these examples.

The major surface 131 is an example of a first major surface. The majorsurface 131 may be referred to as an upper surface or front surface whenappropriate. The switching circuit 51, the filter 61, the matchingnetwork 71, and the chip inductor 120 are disposed at the major surface131. The switching circuit 52, the filters 62 and 63, and the matchingnetworks 72 and 73 are also disposed at the major surface 131, which arenot illustrated in FIG. 3.

The major surface 132 is an example of a second major surface that isopposite to the first major surface. The major surface 132 may bereferred to as a lower surface or back surface when appropriate. The ICdevice 100 is disposed at the major surface 132. The separation of theelements between the major surfaces 131 and 132 is a mere example, andthe separation of the elements should not be construed in a limitingsense.

The IC device 100 is a component (semiconductor integrated circuit)including an electronic circuit formed on and inside a semiconductorchip (also referred to as a die). The IC device 100 is constituted by,for example, a complementary metal-oxide semiconductor (CMOS).Specifically, the IC device 100 is manufactured by a silicon oninsulator (SOI) process. As a result, the IC device 100 can beinexpensively manufactured. The IC device 100 may be formed from atleast one of GaAs, SiGe, and GaN. As a result, the IC device 100 can bemanufactured with high quality.

The chip inductor 120 is an example of a first chip component includingthe inductor L illustrated in FIG. 2.

In the present embodiment, the chip inductor 120 coincides with the ICdevice 100 when viewed in plan view. For example, as illustrated in FIG.3, the chip inductor 120 coincides with the inductor L1 in the IC device100 when viewed in plan view. The chip inductor 120 may coincide withthe inductor L2 instead of or together with the inductor L1.

The switching circuits 51 and 52 are implemented as semiconductorintegrated circuits in the same manner as the IC device 100. The ICdevice 100 may include the switching circuits 51 and 52.

The filters 61, 62, and 63 are each implemented as, for example, asurface acoustic wave (SAW) filter, a bulk acoustic wave (BAW) filter,an LC resonance filter, or a dielectric filter, or any combinationthereof, but the filters 61, 62, and 63 are not limited to theseexamples.

The matching networks 71, 72, and 73 are each implemented as, forexample, a surface mount device (SMD) including an inductor and/or acapacitor. The surface mount device is an example of a second chipcomponent including at least one of the matching networks 71, 72, and73.

The filters 61, 62, and 63 and the matching networks 71, 72, and 73 maybe partially or entirely formed in the module substrate 130 and may beimplemented as an integrated passive device (IPD).

A via-conductor 133 is provided at the module substrate 130. Thevia-conductor 133 is a conductor filling a through via penetrating themodule substrate 130 in a thickness direction. The via-conductor 133electrically couples the connection terminal 101 (refer to FIG. 2) ofthe IC device 100 and the chip inductor 120.

The via-conductor 133 may be constituted by a conductor filling a blindvia formed at the major surface 131, a conductor filling a blind viaformed at the major surface 132, and a planer electrode patternconnecting the conductors filling the two blind vias in the modulesubstrate 130.

The resin member 140 is disposed on the major surface 131 of the modulesubstrate 130 to cover the circuit components disposed at the majorsurface 131. The resin member 141 is disposed on the major surface 132of the module substrate 130 to cover the circuit components disposed atthe major surface 132. The resin members 140 and 141 make the circuitcomponents reliable with respect to characteristics such as mechanicalstrength and moisture resistance.

The post electrodes 150 function as external connection terminalsincluding the antenna connection terminal 90 and the radio-frequencyoutput terminal 91. The post electrodes 150 are disposed at the majorsurface 132 of the module substrate 130 to stand perpendicularly to themajor surface 132. The post electrodes 150 penetrate the resin member141, and one end of each post electrode 150 is exposed from the resinmember 141. The one end of each post electrode 150 exposed from theresin member 141 is coupled to, for example, one of input-outputterminals and/or ground electrodes at a mother substrate disposed on thelower surface side with respect to the radio-frequency module 1.

The shield electrode layer 160 is a metallic thin film formed byemploying, for example, a sputtering technique. The shield electrodelayer 160 covers upper and side surfaces of the resin member 140, sidesurfaces of the module substrate 130, and side surfaces of the resinmember 141. The shield electrode layer 160 is set at a ground potential,and as a result, the shield electrode layer 160 can prevent the entranceof foreign noises into the circuit components constituting theradio-frequency module 1.

3. Effects

As described above, the radio-frequency module 1 according to thepresent embodiment includes the IC device 100 and the inductor Lprovided outside the IC device 100. The IC device 100 includes thelow-noise amplifiers 21, 22, and 23 each having an amplifier transistor,the inductors L1 and L2 respectively coupled to the emitter or source ofthe transistor TR1 and the emitter or source of the transistor TR2, andthe switching circuit 110 coupled between the emitter or source of thetransistor TR1, the emitter or source of the transistor TR2, and theemitter or source of the transistor TR3 and the inductor L. The inductorL is coupled between the switching circuit 110 and the ground in serieswith the inductors L1 and L2 via the switching circuit 110.

The low-noise amplifiers 21, 22, and 23 are integrated together in thismanner, and thus, the radio-frequency module 1 can be downsized.Additionally, since the source inductor of the transistor TR1, thesource inductor of the transistor TR2, and the source inductor of thetransistor TR3 are partially or entirely implemented as the inductor Loutside the IC device 100, spaces necessary for the inductors L1 and L2in the IC device 100 are reduced. As a result, the radio-frequencymodule 1 can be downsized.

Further, the Q factor of the inductor L provided outside the IC device100 can be increased more easily than the Q factor of the inductor Lformed in the IC device 100. The increased Q factor of a part or all ofthe source inductor reduces losses, and consequently, it is possible toenhance electrical characteristics of the low-noise amplifiers 21, 22,and 23.

The low-noise amplifiers 21, 22, and 23 support different communicationbands to each properly amplify a radio-frequency signal in acorresponding communication band. As such, it is possible to implementthe small radio-frequency module 1 including the low-noise amplifiers21, 22, and 23 supporting multiple bands while achieving improvedcharacteristics.

If the source inductor of the transistor TR1, the source inductor of thetransistor TR2, and the source inductor of the transistor TR3 are allprovided outside the IC device 100, characteristics of the low-noiseamplifiers 21, 22, and 23 can be improved. However, in this case, the ICdevice 100 needs external connection terminals for the individuallow-noise amplifiers, which hinders downsizing of the IC device 100. Thepresent embodiment can reduce external connection terminals because theIC device 100 includes the switching circuit 110, and accordingly, it ispossible to achieve downsizing.

Furthermore, for example, the inductance of the inductor L is largerthan both the inductance of the inductor L1 and the inductance of theinductor L2.

Hence, the inductance of the inductor L with high Q factor can occupy asmuch inductance required for the source inductor as possible, and thus,electrical characteristics can be enhanced.

Moreover, for example, the radio-frequency module 1 according to thepresent embodiment further includes the module substrate 130 having themajor surface 131 and the major surface 132 opposite to the majorsurface 131 and also includes the chip components disposed at the majorsurface 131. The IC device 100 is disposed at the major surface 132. Thechip inductor 120 as a chip component including the inductor L coincideswith the IC device 100 when viewed in plan view.

As such, the inductor L is implemented as the chip inductor 120, andthus, it is possible to increase the Q factor of the inductor L.Further, since the components included in the radio-frequency module 1are disposed at both surfaces of the module substrate 130, it ispossible to decrease the area of the module substrate 130 in comparisonto the case in which the components are disposed at only one surface,which achieves downsizing of the radio-frequency module 1. Furthermore,the chip inductor 120 and the IC device 100 coincide with each otherwhen viewed in plan view, and this structure shortens theinterconnection length between the chip inductor 120 and the IC device100. As a result, it is possible to reduce wiring losses and mismatchinglosses due to variations in wirings, which enhances electricalcharacteristics of the radio-frequency module 1.

Moreover, for example, the chip inductor 120 coincides with the inductorL1 or L2 in the IC device 100 when the module substrate 130 is viewed inplan view.

This structure can further shorten the interconnection length betweenthe chip inductor 120 (the inductor L) and the inductor L1 or L2. As aresult, it is possible to further reduce wiring losses and mismatchinglosses due to variations in wirings, which further enhances electricalcharacteristics of the radio-frequency module 1.

Further, for example, the communication device 5 according to thepresent embodiment includes the RFIC 3 configured to process aradio-frequency signal and the radio-frequency module 1 configured tocommunicate a radio-frequency signal between the RFIC 3 and the antenna2.

This configuration enables the communication device 5 to achieve almostthe same effects as the effects of the radio-frequency module 1.

4. Modifications

Hereinafter, modifications to the embodiment described above will bedescribed.

4-1. First Modification

Firstly, a first modification will be described. This modificationdiffers from the embodiment mainly in the positional relationshipbetween the IC device and the input matching networks. The followingdescription mainly focuses on differences from the embodiment and omitsor simplifies descriptions about common points.

FIG. 4 is a sectional view of a radio-frequency module 1A according tothis modification. As illustrated in FIG. 4, the chip componentincluding the matching network 71 does not coincide with at least oneinductor in the IC device 100 when viewed in plan view. Specifically,the matching network 71 does not coincide with both the inductors L1 andL2 in the IC device 100 when viewed in plan view. In the exampleillustrated in FIG. 4, the matching network 71 does not coincide withthe IC device 100 when viewed in plan view.

The chip components including the matching networks 72 and 73, which arenot illustrated in the drawing, do not necessarily coincide with atleast one inductor in the IC device 100 when viewed in plan view.

As described above, the radio-frequency module 1A according to thismodification includes a chip component including one input matchingnetwork for one of the low-noise amplifiers 21, 22, and 23. The chipcomponent does not coincide with the inductor L1 or L2 in the IC device100 when viewed in plan view.

This structure hinders electromagnetic field coupling between thematching networks 71, 72, and 73 and the inductors L1 and L2 in the ICdevice 100, and thus, it is possible to enhance electricalcharacteristics of the radio-frequency module 1A.

4-2. Second Modification

Next, a second modification will be described. This modification differsfrom the embodiment mainly in that a ground electrode pattern isprovided between the IC device and the input matching networks. Thefollowing description mainly focuses on differences from the embodimentand omits or simplifies descriptions about common points.

FIG. 5 is a sectional view of a radio-frequency module 1B according tothis modification. As illustrated in FIG. 5, the radio-frequency module1B includes a ground electrode pattern 134 provided at the modulesubstrate 130. The ground electrode pattern 134 is a planer electrodepattern provided inside the module substrate 130. For example, sidesurfaces of the ground electrode pattern 134 are coupled to the shieldelectrode layer 160, and as a result, the ground electrode pattern 134is set at the ground potential.

As described above, the radio-frequency module 1B according to thismodification includes a chip component including one input matchingnetwork for one of the low-noise amplifiers 21, 22, and 23 and theground electrode pattern 134 provided at the module substrate 130. Thechip component including the one input matching network coincides withthe ground electrode pattern 134 when viewed in plan view.

Because the ground electrode pattern 134 is provided, this structurehinders electromagnetic field coupling between the matching networks 71,72, and 73 and the inductors L1 and L2 in the IC device 100. Thus, it ispossible to enhance electrical characteristics of the radio-frequencymodule 1B.

4-3. Third Modification

Next, a third modification will be described. This modification differsfrom the embodiment mainly in that the inductor provided outside the ICdevice is provided at the module substrate. The following descriptionmainly focuses on differences from the embodiment and omits orsimplifies descriptions about common points.

FIG. 6 is a sectional view of a radio-frequency module 1C according tothis modification. As illustrated in FIG. 6, the radio-frequency module1C includes the inductor L implemented as a planer electrode patterninstead of the chip inductor 120. The inductor L is formed of at leastone of a metal wire such as a stripline or microstripline and avia-conductor.

As such, in the radio-frequency module 1C according to thismodification, the inductor L provided outside the IC device 100 isimplemented as a structure other than the chip inductor 120. This casealso achieves almost the same effects as the effects of theradio-frequency module 1 according to the embodiment.

Others

While the radio-frequency module and the communication device accordingto the present disclosure has been described above by using theembodiment and its modifications, the present disclosure is not limitedto the embodiment.

For example, the IC device 100 may include two, four, or more low-noiseamplifiers. This means that the radio-frequency module 1 may beconfigured to receive and process radio-frequency signals in two, four,or more communication bands. The filters, input matching networks, andselection terminals of switches included in the radio-frequency module 1may be, for example, identical in number to the low-noise amplifiers.

Further, for example, the inductance of the inductor L outside the ICdevice 100 is larger than both the inductance of the inductor L1 and theinductance of the inductor L2 in the IC device 100 in the embodiment,but this should not be construed in a limiting sense. The inductance ofthe external inductor L may be identical to or different from theinductance of the internal inductor L1 or the inductance of the internalinductors L2.

Furthermore, the transistors TR1, TR2 and TR3 may be, for example,bipolar transistors. In this case, the gate, drain, and source of FET inthe above description are replaced with the base, collector, and emitterof bipolar transistor. At least one inductor included in the IC device100 is coupled to the emitter of a bipolar transistor functioning as anamplifier transistor.

Moreover, for example, the electronic components including the IC device100 are disposed at both surfaces of the module substrate 130 in theembodiment, but this should not be construed in a limiting sense. Allthe electronic components included in the radio-frequency module 1 maybe disposed at only one surface of the module substrate 130.

Further, for example, the external connection terminals of theradio-frequency module 1 are implemented as the post electrodes 150 inthe embodiment, but this should not be construed in a limiting sense.The external connection terminals may be implemented as bump electrodes.

Furthermore, for example, the communication device 5 is a receiver inthe embodiment, but this should not be construed in a limiting sense.The communication device 5 may be, for example, a transceiver. In thiscase, the radio-frequency module 1 may include a transmit circuitincluding, for example, power amplifiers and transmit filters.

In addition, all forms obtained by making to the embodiment andmodifications various changes that occur to those skilled in the art andall forms implemented as any combination of components and functionsaccording to the embodiment and modifications without departing from thescope of the present disclosure are embraced within the presentdisclosure.

The present disclosure can be used as a radio-frequency module providedat the front-end for various communication devices such as a mobilephone.

While preferred embodiments of the disclosure have been described above,it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the disclosure. The scope of the disclosure, therefore, isto be determined solely by the following claims.

What is claimed is:
 1. A radio-frequency module comprising: anintegrated circuit (IC) device; and an external inductor providedoutside the IC device, wherein the IC device includes a plurality oflow-noise amplifiers including a plurality of amplifier transistors inone-to-one correspondence, one or more inductors coupled to one or moreof the plurality of amplifier transistors, each inductor being coupledto an emitter or source of a corresponding one of the plurality ofamplifier transistors, and a switching circuit coupled between anemitter or source of each of the plurality of amplifier transistors andthe external inductor, and the external inductor is coupled between theswitching circuit and ground in series with each of the one or moreinductors via the switching circuit.
 2. The radio-frequency moduleaccording to claim 1, wherein an inductance of the external inductor isgreater than an inductance of any of the one or more inductors.
 3. Theradio-frequency module according to claim 2, further comprising: amodule substrate including a first major surface and a second majorsurface that is on an opposite side of the module substrate than thefirst major surface; and a first chip component disposed at the firstmajor surface, wherein the IC device is disposed at the second majorsurface, the first chip component includes the external inductor, andfrom a plan view of the module substrate, a footprint of the first chipcomponent coincides with a footprint of the IC device.
 4. Theradio-frequency module according to claim 3, wherein from the plan viewof the module substrate, the footprint of the first chip componentcoincides with the one or more inductors in the IC device.
 5. Theradio-frequency module according to claim 4, further comprising: asecond chip component including an input matching network for one of theplurality of low-noise amplifiers, wherein from the plan view of themodule substrate, the footprint of the second chip component does notcoincide with any of the one or more inductors in the IC device.
 6. Theradio-frequency module according to claim 4, further comprising: asecond chip component including an input matching network for one of theplurality of low-noise amplifiers; and a ground electrode patternprovided at the module substrate, wherein from the plan view of themodule substrate, the footprint of the second chip component coincideswith the ground electrode pattern.
 7. The radio-frequency moduleaccording to claim 3, further comprising: a second chip componentincluding an input matching network for one of the plurality oflow-noise amplifiers, wherein from the plan view of the modulesubstrate, the footprint of the second chip component does not coincidewith any of the one or more inductors in the IC device.
 8. Theradio-frequency module according to claim 3, further comprising: asecond chip component including an input matching network for one of theplurality of low-noise amplifiers; and a ground electrode patternprovided at the module substrate, wherein from the plan view of themodule substrate, the footprint of the second chip component coincideswith the ground electrode pattern.
 9. The radio-frequency moduleaccording to claim 1, further comprising: a module substrate including afirst major surface and a second major surface that is on an oppositeside of the module substrate than the first major surface; and a firstchip component disposed at the first major surface, wherein the ICdevice is disposed at the second major surface, the first chip componentincludes the external inductor, and from a plan view of the modulesubstrate, a footprint of the first chip component coincides with afootprint of the IC device.
 10. The radio-frequency module according toclaim 9, wherein from the plan view of the module substrate, thefootprint of the first chip component coincides with the one or moreinductors in the IC device.
 11. The radio-frequency module according toclaim 10, further comprising: a second chip component including an inputmatching network for one of the plurality of low-noise amplifiers,wherein from the plan view of the module substrate, the footprint of thesecond chip component does not coincide with any of the one or moreinductors in the IC device.
 12. The radio-frequency module according toclaim 10, further comprising: a second chip component including an inputmatching network for one of the plurality of low-noise amplifiers; and aground electrode pattern provided at the module substrate, wherein fromthe plan view of the module substrate, the footprint of the second chipcomponent coincides with the ground electrode pattern.
 13. Theradio-frequency module according to claim 9, further comprising: asecond chip component including an input matching network for one of theplurality of low-noise amplifiers, wherein from the plan view of themodule substrate, the footprint of the second chip component does notcoincide with any of the one or more inductors in the IC device.
 14. Theradio-frequency module according to claim 9, further comprising: asecond chip component including an input matching network for one of theplurality of low-noise amplifiers; and a ground electrode patternprovided at the module substrate, wherein from the plan view of themodule substrate, the footprint of the second chip component coincideswith the ground electrode pattern.
 15. A communication devicecomprising: a signal processing circuit configured to process aradio-frequency signal; and a radio-frequency module configured tocommunicate the radio-frequency signal between the signal processingcircuit and an antenna, the radio-frequency module including anintegrated circuit (IC) device, and an external inductor providedoutside the IC device, wherein the IC device includes a plurality oflow-noise amplifiers including a plurality of amplifier transistors inone-to-one correspondence, one or more inductors coupled to one or moreof the plurality of amplifier transistors, each inductor being coupledto an emitter or source of a corresponding one of the plurality ofamplifier transistors, and a switching circuit coupled between anemitter or source of each of the plurality of amplifier transistors andthe external inductor, and the external inductor is coupled between theswitching circuit and ground in series with each of the one or moreinductors via the switching circuit.
 16. The communication device ofclaim 15, wherein an inductance of the external inductor is greater thanan inductance of any of the one or more inductors.
 17. The communicationdevice of claim 15, wherein the radio-frequency module furthercomprising: a module substrate including a first major surface and asecond major surface that is on an opposite side of the module substratethan the first major surface; and a first chip component disposed at thefirst major surface, wherein the IC device is disposed at the secondmajor surface, the first chip component includes the external inductor,and from a plan view of the module substrate, a footprint of the firstchip component coincides with a footprint of the IC device.
 18. Thecommunication device of claim 17, wherein from the plan view of themodule substrate, the footprint of the first chip component coincideswith the one or more inductors in the IC device.
 19. The communicationdevice of claim 17, wherein the radio-frequency module furthercomprising: a second chip component including an input matching networkfor one of the plurality of low-noise amplifiers, wherein from the planview of the module substrate, the footprint of the second chip componentdoes not coincide with any of the one or more inductors in the ICdevice.
 20. The communication device of claim 17, wherein theradio-frequency module further comprising: a second chip componentincluding an input matching network for one of the plurality oflow-noise amplifiers; and a ground electrode pattern provided at themodule substrate, wherein from the plan view of the module substrate,the footprint of the second chip component coincides with the groundelectrode pattern.